The invention relates to a process for measuring laser power, wherein an electrically actuable measuring wire or the like having a temperature-resistant electrical resistance is subjected to a relative reciprocatory movement transversely over the beam cross-section.
To measure laser power, it is generally known to provide a detector to absorb the whole beam. During the measuring period it is impossible to process a workpiece using the laser beam. It is also generally known to measure a portion of the laser beam using a reflecting element or a partially transmissive optical system, so that the measurement can in principle be performed even during the processing of the workpiece. However, the reflecting element or the partially transmissive optical system may have an adverse effect on the laser beam or itself be destroyed or damaged by excessive radiation powers or intensities. For this reason as a rule it is impossible; to perform measurement between the focusing optical system of the laser beam and the workpiece.
EP B1 0050159 discloses a process having the steps mentioned hereinbefore. That process uses the temperature dependence of the electrical resistance of the measuring wire to obtain a measured value for the power of the laser beam. However, the measured value is adversely affected by interferences, for example, different heat transfer resistances depending on convection.